The development of computer hardware is a continuously changing technology. To match newly developed hardware components, the chassis that surrounds the hardware of the computer must be adapted accordingly. Today, the computer chassis must not only accommodate a variety of different input and output ports, but must also provide an easy access for exchanging pieces of hardware when the operator wishes to upgrade the computer.
Recently, the NLX motherboard form factor was introduced in the computer market. It is expected that this form factor for motherboards will become increasingly popular, and that a number of computer hardware manufacturers will produce computers capable of being provided with a motherboard conforming to the NLX standard. The NLX form factor is thoroughly described in "NLX Motherboard Specification," published by Intel Corporation, 1997.
A computer chassis in conformity with the NLX form factor includes a mother board (circuit), an input/output (I/O) back panel, and a riser card, rising vertically from the circuit board. The circuit board includes a number of components of the motherboard, most essentially the processor of the motherboard. The riser card receives a connection from the power supply of the computer, and also contains connections to peripheral components of the computer such as a floppy drive, a CD drive, and the hard disk. The I/O back panel contains connectors for attaching external units such as the keyboard, the mouse, etc.
A conventional (ATX) computer chassis typically has an I/O opening on its back wall into which the I/O back panel can be fit when the motherboard is inserted into the computer. The I/O opening provides access to connectors on the I/O back panel when the computer is fully assembled. In addition to the I/O opening, there are typically a number of expansion card openings which an operator may use for installing and accessing optional expansion cards and cables in the computer. Examples of common expansion cards include video input and output cards, etc. Expansion card openings which are not being used are typically covered with plates, doors, etc.
Typically, a chassis having an NLX I/O back panel opening and expansion slots, is manufactured by providing two separate openings in a back wall of the chassis. Generally, a first opening conforming to NLX standards is punched in the back wall, and a second opening is punched in the panel for the expansion slots. Typically, the opening for the expansion slots is large enough to hold a slot bracket comprising, for example, three expansion slots. The slot bracket is manufactured separately and inserted into the opening for the expansion slots and fastened with screws or by welding, or any other method. The punching out of the two openings requires a precise manufacturing procedure. It is important that each opening is punched in exactly the right place so that components within the chassis properly align with the openings. It is also important that the openings are not punched too close to each other, because the structural integrity of the back panel is essential in supporting the chassis against the moderate amount of force which is typically used when connectors are inserted into the connections or expansion slots or removed from the same. The computer chassis helps maintain an EMI (seal) contact. If a side wall of the chassis, for example, is removed by sliding it out of the remaining computer chassis when for example a mother board is inserted or replaced, there is a chance the user will forget or omit to replace the sliding side wall when reassembling the computer. The missing side wall may subject the computer to detrimental EMI effects.
A conventional personal computer chassis also typically includes a top cover for enclosing the internal components of the computer. By removing the cover, the interior of the personal computer becomes accessible. The interior of the computer is commonly divided into two halves. In the first half, there is a motherboard and various input and output ports. There may also be a fan which draws air from the outside of the chassis into the chassis to provide cooling for the electrical components. In the other half of the interior, the power, supply unit is typically housed, as well as floppy drives, CD drives, and hard drives.
To gain access to the motherboard located in the first half of the interior, a side wall of the chassis is typically required to be removed. In this regard, it is desirable for the side wall to be removed or otherwise displaced from the chassis with minimal effort to allow the motherboard to be easily accessed. Additionally, it is desirable for the side wall to provide structural support of rigidity between the front and back walls of the chassis. Structural integrity is essential in a computer chassis, because the computer contains many components which are sensitive to mechanical force and shocks. Furthermore, absent sufficient structural support, corners of the chassis can become skewed thereby causing aesthetically unpleasing gaps to form between the chassis top cover and a face cover typically mounted on the front of the chassis. As mentioned, the computer chassis should help maintain an EMI shield for electronic reliability.